usercontrols... collection value isnt saved when changed at design time

[MrPolite]

hmm I dont know how to explain it because I dont really know what I'm doing
I have a class which inherits from CollectionBase. And I have a public property in my usercontrol of that type, so:

Public myClass:Inherits CollectionBase
End Class
 
...
'In user control:
<Browsable (true)> _
Public Property myClass SomeCollection
'Get, Set....
End Property

now when I add the usercontrol to my form, and I look at the SomeCollection property, I can click on a little "..." button and the VS Collection Editor shows up... I can add items, but the thing is that the items all disappear after I run the project (so when you check the SomeCollection property, there is no items in the collection anymore, all get cleared)....
I think I'm doing something fishy here, but I cant figure out what... anyone else ever had this problem?
let me know if I'm not explaining enough